Did you know [#06]

Here's one you probably think I am lying about: between 1922 and 1927 radio stations were required to shut down for 24 hours a day once a week.

The reason for this was to allow people to hear radio stations not broadcast in their local area. 

A 50,000 watt station like KMOX in St. Louis (provided it was around back then) would come in rather clearly (at night with clear skies) in Chicago or Dallas if local stations weren't broadcasting.